Transmission



Feb. 24, 1953 A. Y. DODGE 2,629,265

TRANSMISSION Filed April 30, 1948 3 Sheets-Sheet l 5/ l v 5a 73 ,jf /arza gaajge,

Feb. 24, 1953 A. Y. DODGE 2,629,265

TRANSMISSION Filed April 30, 1948 3 Sheets-Sheet 2 Feb. 24, 1953 A. Y. DODGE 2,629,265

' TRANSMISSION Filed April 50, 1948 1 z Sheets-Sheet s M$a@ag sion, embodying the invention;

Patented Feb. 24, 1953 UNITED STATES PATENT OFFICE.

TRANSMISSION Adiel y. Dodge, Rockford, 111. Application April 30, 1948, Serial No. 24,158 8 Claims. (01. 74-645) This invention relates to transmissions; and more particularly to variable peed and torque transmissions of the type adapted for use on automotive vehicles.

It has been proposed to employ various types of transmission on automotive vehicles including transmissions utilizing hydraulic torque converters alone or in combination with variable ear sets. It has further been proposed to control such transmissions both manually to obtain any desired driving condition at will and automatically to change the driving condition in response totoperation of ,the transmission. The present invention has for one of its objects the provision of a transmission of this type which can be controlled either automatically or manually Another object is to provide a transmission in which any one of a plurality of forward speed ranges and at least one reverse drive can be manually selected at will and in which changes from one to another forward driving condition can be automatically effected.

Still another object is to provide a transmission in which the ratio changes are produced by fluid pressure developed by operation of the transmission under the control of a manually operable valve. In the preferred construction the transmission operates a fluid pump to upply pressure for changing the transmission ratio and which may also supply operating fluid to a hydraulic torque converter forming apart of the transmission. 6 i

,Afurther object isto provide a transmission in which the ratio changesare effected automatically in response to the'pressure developed by a pump driven by'the transmission output shaft.

According to one feature of the invention, the same pump may beconnected to the transmission control means to operate the same when the driven shaft is turning and theengine is stationary as, for example, in pushing the vehicle to start the engine. A still further object is to provide a transmission in which a manually operable valve controls the change of gear ratios and also controls supply of operating fluid to an automatically operable valve so that the transmission may be operated manually or automatically at will.

The above and other objects and advantages of the invention will be more readily apparent whenread in connection with the accompanying drawings, iniwhich- Figure 1 is a diagrammaticview: of a transmis- Figure 2 is a diagrammatic end view of the gear unit of the transmission of Figure 1 looking from'[ the right in Figure 1 with parts omitted;

Figure 3 is a diagrammatic side elevation. with.

parts in section illustrating the manual control valve of Figure 1;

Figure 4 is a diagrammatic view with parts in.

the line 6-s or differential gearing to the driving wheels of a. ,vehicle.

The transmission comprises a hydraulic torqu converter indicated generally at 12 which may be any desired type of torque converter suchas is shown, for example, in my Patent No. 2,270,515 or No. 2,287,374. This unit when properly filled with fluid serves to transmit the torque of the driving shaft ID to an intermediate shaft IS in infinitely varying speed and torque ratios between the maximum torque multiplication for which the unit i designed and a direct one to one drive. The intermediate shaft is connected to a compound planetary gear set which connects it to the driven shaft l l and which is capable of pro-'{ viding a plurality of driving conditions includingseveral forward driving ratios and one reverse ratio. r

As shown, the planetary gear set comprises Sun gear l4 connected to the intermediate shaft and meshing with elongated planet pinions 15 rotatably mounted on a carrier [5 which is connected to the driven shaft H. The pinions 15 extend beyond the Sun gear l4 into register with a second sun gear ll which is of such a size that it will not mesh with the pinions l5. Idler pin ions H3 mesh with the sun gear I! and with a ring gear l9 and with the planet pinions l5 as best Seen in Figure 2. The ring gear I9 is adapt ed to be held stationary by a brake 2! for reverse drive, and the sun gear I! is connected to a brake drum 22 adapted to be engaged by a brake 23 for low speed forward drive. A friction clutclr mechanism indicated generallyat 24 is provided to connect the intermediate shaft 13 directly to the drum 22 When the clutch is en= gaged the sungears l4 and I1 will be connected When theacan'l .bar ismoved to the right, 'as'seen in Figure 1, the brake 23 will be engaged, and

when it is moved to the left, the brake 2| will be engaged. In the neutral position illustrated, :both brakes are released.

The cam bar is shifted by a fluidpressure mechanism comprising a cylinder 28' having a piston 29 therein which is connectedt'oi the cam bar. The cylinder has end ports 31 and .32 and a center port 33 whichmay be supplied with pressure. or connected to exhaust in order to effeci'fthe desired movements of the piston; The

clutch 24'isi operated by'an annular piston-'35) supplied with pressure through a pipe 35"so that when pressure 'is supplied to'the piston 35 the clutch will'beenga'ged.

piston 34*;is (controlled by a manual valve indicated generally; at 36. The valve, as seen in Figure" 3, comprises an outer cylinder formed with" a plurality of vertically and" circumferen tially spaced ports controlled by a piston 31 slid able axially 'inthe' cylinder. The piston is adapted to be moved by a hand lever 38 which'may be mounted on the steering column and which carries a' pointer 39 movable over a dial indi-- catedat 41 and which may bemarked as shown.

"Thepiston 31 'oftheva-lveis formed with an elongated inlet port fizwhich is in constant communication with a pressure supply pipe 43- and with an elongated exhaust port 44 which is-in constant communication with a discharge pipe 45' leading to a liquid sump. The'elongat'ed ports 142*a'nd4lare connected to crossports arranged at different levels for selectively connectingthe' inlet and exhaust ports toarplur'ality of lateral ports in the valve casing which aiefinturn connected to the severaloperat'ed units -of the transmission. It' will be understood thatthe're may be a plurality of such connections" at'each' level'so that as the valve is moved axially in'the valve casing the desired ones of the ports a 1 Supply of pressure to the cylinder 28 and-the may be connected to a'pressure source, others may be connected tothe sump and still others may beclosed. a

The brakes and clutch are also adapted to be controlled automatically by an automatic Valveindicated generally'at' lliand which comprises a cylinder having a center inlet port 4? anda 'plu-' rality 0f controllable' ports 43, 49' and 5|. -A' plunger" 52 is slidable in the automatic valve cylinder and is provided with a passage 53'to connect the ports 43, 49 and 51-, if desired. 7 The plungeris adapted to'be moved'automatically in response to operating conditions of the transmission as will be'described hereinafter.

*The valve 36 is provided with a plurality of ports" at different positions for operating the control mechanism to'produce a low gear drive. These ports are indicated diagrammatically in both Figures 1 and 3 'bytheletter Z. Similarly the v'alve is-provided with a plurality of ports in different positions for producing a high-ratio operation, all-of such ports being indicated in Figures land 3'by the letter h. Thevalve also has a series ofneutral ports indicated in Figures cylin'der2'8, as shown in Figure 1.

1 and 3 by the letter n and a series of reverse ports indicated by the letter 1. There is also an automatic port indicated by the letter a and an automatic sump port indicated by the letters sa. It will be understood that Where the same letter occurs at different levels in Figure 3 it indicates either a plurality of separate spaced ports which have a common pipe connection or interconnectionsthrough-thelvalve plungerabetween the several ports 1 having'lthe same'lettersoi that they are all interconnected in the valve plunger itself.

-=A1so where several different ports appear at the same level, they are circumferentially spaced as indicated in Figure 1 with passages in the valve plunger .t provide the desired interconnections between the ports.

.-.Ail1.:o'f the :neutral ports indicated at n communicatewith the pipe 33 at the center of the The Z ports all communicate with the pipes 3| and 51, as shown" in Figure 1; the 1' ports allcoinmunicate with the pipe 32 at the right ofthe"cy1inder128; as shown-in Figure 1; and the af po'rt communie cates with the pipe 4'! to supplyliquidto -thefau tomatic valve 48. In -addition the po'r t 5 l-"isia1s0 to the pipe 33.

-As the valve isoperated to its several posh' tions to move the indicator to [the -point*P"for park-and N for-neutral; L for low,H for.high,-A

for automatic andR for'reverse', theseveral ports in the valve will 'be either open to pressure asi indicated by p onthefollowing-chart, open" tosump as indicated by s on the followingchart-or closed as indicated by con-the following chart.

p=open to pressure.

s'=open to sump.

Thus in the parking position fiu'idis admitted to the left of the cylinder .28 and to the piston 34 to engage both theclutch' 2'4 and the brake23 so that the sun gear H is locked to they intermediate shaft 13 and both are held stationary. Thus at thisltime the vehicle is held against any move'- ment. In neutral the parts will be in'thepo-sition shown with both brakes 2| and 23' disengaged and the .clutch' 2 4 disengaged soth'at no torque can be transmitted throughthe gearing. For low the port 11. is closedand pressureis ad mitted to the port 1' tomove'the'piston 2-9 to the' right thereby engaging the brake 23 to hold the sun gear I l stationary. At this timethe sun gear I4 drives through the planet and idler pinions which'later roll around the-stationary sun'gear l! to turn the driven shaft forward at reduced speed. In the high positionboth brakes 2'land 2-3 are released, and the clutch 24 is engaged so that the engine drives directly through the torque converter and the locked gear unit to-the driven shaft. I In automatic the'porlt a'--is= connected to a source of fluid under pressure through the manual valve so that when the'valve 5 2moves it willautomatically-controlthe brake 23 andthe clutch 24. In the position ofvalve"5 2'shown- Ports'inautomatic Polts in hand valve g i n l h a r .sa a land'n .h' so 6 s c s c c I c c p s s c s i s I c s' c s n c c c s c s c c c p s s .1) 'Auto .Auto s c p s s s s s aecciccs 53 th port 48 which is connected to them pass suppliedtothe p'istonflthrough theport "to engage the clutch for high gear operation." While the position of automatic valve 52 1 shown isin dicativebf the low" position, the transmission remainsin the parked position because no "fluid position shown.

m the --va1ve. the valve plunger 52 moves to the-rightthe port -l will be-connected tothe sum-p through port 49 and fluid will be e l'nder Z Bjto move the piston 28 to the left and engage the brake 2|; At this time the idler pinions" '1 ftvillk roll around on the stationary ring goat laftoilcauselthe'carrier -andthe"-driven shaft toturn in reverse." 1 y Tosupply fluid for operating the clutches and bralgesas described, a primary fluid pump 56-i's provided drivenfby agear 51 on the intermediate shaft l3. The pump 56 receives fluid from a sump, not sho'wnjand pumps it into a distributing line 5-8,.which leads through the accumulator '58 tofthejpressuresupply, port in the valve which communicates withflthe elongated port 42. Preferably, 'a' bypass connection it is provided connectedto the pipe'lit through a pressure responslve valvejji ljto supply operating liquid to the torque (converter l2, After a predetermined pressure has built upinthe accumulator 59, the valve fit-{will open tocirculate liquid through the torque convertefthereby to maintainit full and. to produce a cooling efi-ect. Preferably a pressurefresponsive relief valve 63 isprovided dis charging Ito the. sump to prevent building up an undesirably high pressure in thetorque converter. f

Automatic duced in responseto a fluid pressure which is in turnfresponsive to rotation of the driven shaft mechanism." The cylinder 6'6 ycontainsa piston 51 urged .to the left by a spring .68 and connected directly tothe valve plunger 52 to move it. The

pressure -de veloped in the cylinder (:66 i gcontrolled by a; control mechanism 1'5, as shown; in Figure .4, which is substantially similar .to that controljof thetransmission to shift, the valve plunger 52 of Figure l ispreferably promioreparticularlydescribed and claimed in. my v Rece tive-2,372,817. n V

Asshown in Figured, the pump 64 receives liquid from a sump indicated generally at H and discharges pastfan overloadrelief valve/12 and a transfer valve 13 whose purpose will be described hereinafter i'ntda pipe 14 leading to the left end-"lif the cylinder 66. Thepipe I4 also connects to a valve unit indicated generally at 15by"means of' which'the pressure acting on thepiston '61 isregulated. The valve unit comprises an elongated passage 16- communicating with 'thefpipe 14. andhaving areturn passage I1 leading therefrom 1120 thesurnppyCommunication fr'om :the passage -16 'to the sump is con: trolled-primarily" by a pressure" relief valve 18 whichis normally urged toward its closedjposi tiontby. apair of. spr s. an 8 e pri 19 seatsjagainst iitherendgof 1 a 1 lever connected to.

a shaft 82 which is manually adjustable" through a handle 83' movable over a segment 84 to I com-1:1: trol the point at whichthe-transmisslon :will shift from lowto high thereby-toalter itsautomatic performance characteristics. The spring 8i similarly seats against the endof arlever on a shaft 83 which is connected through a link .8 !v

By adjusting the spring loading on the valve through the lever 83 andthrough the cam mech- A anism on the accelerator pedal, the speed at which the shift will occur canbe changedg'the greater the spring loading the lower thespeed at which the shift takes place.

Under certain driving conditions, it maybe desired toquickly manually shift the transmisision into low speed drive. This may be done' by -i depressing the accelerator pedal allthe way down below the full openthrottle position. v So doingwill prevent supply of pressure to the cylinder 66. For this purpose a slide valve88 isarranged in the valve body to control: communication between the passage 16 and a bleed passage 89. The valve 88 is controlled through ashaftQl which is connected by 'a link 92 toa bell crank 93 adjacent the cam 86. The cam is provided with a pair of projecting ears 94 and 95movable in a path to engage the end of the bell crank 93. When the accelerator pedal is fully olethe passage 16 directly to the bleed passage 89.

At this time no pressure can be built up in the. cylinder 65 so that the transmission will return. to low gear. To returnto normal automatic operation, it is necessary only to release the acceler ator pedal so that the ear 94 will rock thebell crank lever 93 to the position shown to closethe At this time pressurein the cylinder V 66 is controlled automatically by the valve 18 valve 88.

as described above.

torque.

is placed in either the low or high position.-

With the transmission and control mechanism as described, the operator can select any ratio in which he wishes to operate simply by moving the control lever 38 to the desired position so that complete manual selectivity is provided at all times. For automatic operation the control lever is moved to theautomatic position which will initially place the transmission in itsf low rangecondition. As the driven shaft speedin creases, the transmissionwill automatically shift a to its high range position and can automatically change between low and-high as joperating con: f ditions demand; It noted, howeverfithati at pressed,the ear 95 will engage the bell crank I 93 and shift the valve 88 to the left to open gaze-26s.. a

7 anyitimetheioperatorxcan-overruletheautomatic I operation.ibyh-shifting to a-desired': selected ..poSi'-- I tionrat which time. the automatic control mechanisnrsis made ineffective-by cutting off :thesupply. of operating fluid :to the automatic-valve Theclutch 24w shown in-Figure- =1 might be changed-to a mechanically actuated over center. clutch-more like clutch-I2I-shown in Figure 5. Such .changewill' make a mechanically locked low and :high 'gear in the parking position Figures and 6' illustrate an alternative trans mission: arrangement adapted: to be controlled either manually or: automatically in the: same mannen as the transmission. of Figures 1 to A by similar control mechanism. A Thetransmission of Figures'5 andtdis adapted: to connect a driving ph'aft. IMP to-:a drivenshaft I0 I and com-.- prises a hydraulictorque converter indicated gen-1 erally at Ill2connectedto the driving shafth The 'IlOI'QllGiCOIWBIUGI is shown as being of the. type 7 more: particularly described and ,claimed in my -Patent.No.".-'2,421;l'90 and comprises a speed responsive friction clutch-1H1? connected to-=the,: driving. shaft I0 and'adapted'to connect -it to an impeller r I 04 in the torque converter. The impellerrcarries a set of fixedwvanessand a set of auxiliary-vanesxl'ili'i which'are normally rotatable relative to theimpeller structureand are 'con-'.- nected ther-eto above a predeterminedspeedby a speed responsive clutch "I 03. Thetorque. converter includes a double-rotor having spaced sets ofvanesclfll I'M- and IIl9-which are connected to aamrintermediate.--shafti I I I. Sets of stator: vanes II2-and-I I3 are arranged between the spacedrsets: of-'.-rotor"vanes and are normally v held against reverse rotation: by one-way brakes I I4. While one particular typeof torque coni verter has-'beenshownand described, it will be--- understood that torque-converters=ofiother types could be'employed; if desired.

The intermediate shaft -'I I I =drivesa compound planetary'gear set which is shown as being identical with'a gear set more particularly described and claimed in Y my copending application Serial 7 No.--660;232,"filed-Apri1 6; 1946, now PatentNo. 2,570,327-of-wh-ich this application is a continuation in part.- In'this gear set a first sun-gear I I5 is connectedto the intermediate-shaft III=and meshes with compound planet .pinions: having central portions II6 meshing withthe sungear 5 H5. .The -pinionsinclude-larger: portions. II'I meshing with "a; second sun gear II 8 which is connected-to'a brakedrum I I9, The brake .drum can beheld stationary-by a brake 12!! or canbe connected-to the intermediateshaft III'bya friction-"clutch vI2I operated by a collar. l22, The pinions include. a third=-.reduced portion. 123. meshing with idlerpinions I24 as. best seen in Figure-6. The idler pinionsmesh inturn with a third sun gear .I25-and with'a ring gear I26. 0 The. ring gearcan beheld stationary. when de-. sired by'a' brake I21, and thesungear I.25 is con.- nectedtoa brake drum. I28 which can be held stationary-by a brake I29. The pinion portions IIB :mesh with a ring gear ,I3I (which can be held stationary by a brake I 32.

The several brakes and clutches may be controlled by one orv more cam bars I33 having spacedcam-projections.I34: I35fI3Ii', I31 and I33 l thereon: The. projection I34 may cooperate with an operating .rod. I.3!l.for the brake I29, the projectionI35-cooperateswithanoperating rod I40 forqthegbmkgfly the. projection I35c'ooperates withanoperating rod I4I for the brake I321and the projection- I 31 "cooperate with an operating rod-.142 .for the brake I 20.- The projectiond 38. moves .an-operating .rod I 43 which is connected through a bellcrank I. 44.to the clutch operating, collar I 22 to control the clutch. I 2 I Thecam bar I33 may be movedto operate the several operating "rods through one or .more fluid motors each of .which includes a cylinder .I45 having a piston I46 therein whichmay becontrolled similarly to the piston 29 ofFigure .1 to move to any one of a plurality of positions-by ports I41.

The parts as shown are in the neutral position withallof the brakesand the clutch disengaged so :that no torque: can be transmitted through, the gear set. For low geardrive the camrod I33 is shifted one step to the left to engagethe.

clutchand holdthe ringgear I-.3I stationary. ,At

this. time the sun gear drives through th pinion portions .1 I6to causethem .to. roll around. the ring gear at .low. speed to drive the gearcarriel'. and the drivenshaft. forward. at low speed. For. second. speed thev cam rod is shiftedfurther to f the left to disengage the brake I32 and engage the brake I29. At thi time the. sungear. I25Lis held stationary-sothatthe.idler pinions I241can roll around. it.. The idler. pinions. are. driven. through the compound planetpinions. I23 from.. the sun gear H5 and will turn the gear carrier.

forward at a small speed ratio. For direct forward drive the cam .bar is shifted still further to the left to disengage the brake I29 and engage the clutch I2I. At. this time the gearsetis locked. to turn as a unitso that-the intermediate shaft is connected directly to the driven shaft.

For overdrive the ca'mbar is shifted still furgear carrier forward at a higher-speed than the intermediate -shaft.' For reversethe cam bar is shifted to the right to engage the brake I2'I.an'd

hold'the ring gear I26 stationary. At this time theidler. pinions I24.wil1 roll around the stationary ring gear to turn. the gear carrier in a,

reverse direction;

The intermediate shaft I I I drives a pump corresponding .to the pump 56of Figure 1 and shown as including a pinion I48 keyed to the intermediate shaft and meshing with a second pinion I49.' The pinions are enclosed by a house ing I5I so that they form a gearpump to supply fluid to the control system a described in 0011-,

nection with Figures 1 to 4.

Similarly the driven shaft IIlI drives a pump I52 through a worm .I 53 and worm gear I54. Tli'e pump I52 corresponds to the pump.64 of Figures 1 to 4 and may function in the same mannerto provide automatic operation and to .supply.op-

eratingl fluid for-the clutches and brakes to. start the'veh-icle engine by pushing the vehicle.

The clutch I2I i'sypreferably'operated by a mechanical over-center'mechanism-so that once it i engaged it will be held-engaged until it is positively released. For this purpose the collar 3 I22 "is formedwith an annular cam surface I55; whichcengages 'the lower .end of a clutchoperat- 7 ing' lever I56. When thecolla'r'rI22 "is shifted to i the right it will camthe lever I56 clockwise :to-

engage the clutch I 2I and the camangle is such e ital??? ss to l si-t nia is ngage theprojection I38 from the'rod I43.

,This arrangement isparticularly useful .in

parking since it maintains the clutch engaged even ,though the vehicle should be parked long 1 .enoughtolose the normal operating pressure for ,the,c1utch., It will be apparentthat a similar operating arrangement couldlbe provided for the several brakes to insure that they will eheld engaged-even-though the fluid pressure is lost.

. gear ratio thereof, fluid pressure operated means control the controllable elements, aQ-pump driven by one of the shafts, a manually operable valve connecting the pump to the pressure D- erated means and controllable to operate said elementsselectively to select any desired gear ratio of the gear set at will, a second pump driven by While several embodiments of the invention have been shown and described in detail herein, it will be understood that these are illustrative only'and arenot' to be taken as a definition of the scope of the invention, reference being bad for this purpose .to theappendedclaims.

What is claimed is:

m i 1. A transmission for connecting a driving member to a driven shaft comprising a hydraulic if torque converter connectedto the driving sh-aft, an intermediate shaft driven by the torque con verter,, a variable speed, gear set connecting the intermediate shaft to the driven member, ooh- I trollable elements in the gear, set to change the gear ratio thereof, fluid pressure operated means ,to control the controllable elements, a, pump driven by :one of the shafts, a manually operable v make the automatic-means operative or inoperative at la 33? it l 2. A transmission for connecting a drivin shaft to a driven member comprising a hydraulic torque converter connected to the driving shaft, an intermediate shaft driven bythe torque con verter, a variable speed gear set connecting the intermediate shaft to the driven member, 0011-! troll-able elements in the gear set to change the gear ratio thereof, fluid pressure operated means to control the controllable elements, a pump driven by one of the shafts, a manually operable valve connecting the pump to the pressure operated means and controllable to operate said elements selectively to select any desired gear ratio of the gear set at will, a second pump driven by the driven member, automatic means responsive to the pressure developed by the second pump and connected to the fluid pres-sure operated means to control the controllable elements, a connection from the manually operable valve to the automatic means to supply operating fluid to the automatic means, means in said manually operable valve to open or close said connection to make the automatic means operative or inoperative at will, and a connection from the second pump to the manually operable valve to supply fluid thereto when the driven shaft is turne.

3. A transmission for connecting a driving shaft to a driven member comprising a hydraulic torque converter connected to the driving shaft, an intermediate shaft driven by the torque converter, a variable speed gear set connecting the intermediate shaft to the driven member, controllable elements in the gear set to change the the driven mem'ber, automaticmeanresponsive to the pressure developed by the second pump and connected to the fluid pressure operated mean to control the controllable elements, a connection from the manually operable valve to the automatic means to supply operating fluid to the automatic means, means in said manually operable valve to open or close said connection I "to make-the automatic means operative orinoperative at will, and connections from the pumps to the torque converter to supply operating fluid thereto.

4. A transmission for connecting a driving shaft to a drivenshaftcomprising a hydraulic torque converter connected to the driving shaft,

an intermediate shaft driven by the torque con verterya compounddifferential gear set includjing a plurality of relatively rotatable elements one of which is connected to the intermediate shaftand anotherof which is connected to the driven shaft, brakes for selectively holding others of theelements against rotation to produce different gear ratios, a clutchto connect the intermediate shaft to an element of the gear set other than said one element tolock the gear set for direct drive therethrough, fluid pressure operated, means to control the brakes andclutchfa manually operablevalve to control the supplyof fluid pressure selectively to any one of the pressure operated means thereby to select a desired gear ratio of the transmission at will, a. fluid pump driven by the driven shaft, a v-alvebperable automatically in response to the pressure developed by the pump to control thesupply of fluid pressure to the pressure operated means, means in the manually operable valve tofmake the last named valve effective or ineflec'tiveet 45 will, and'means independent of the last names valve to connect the fluid pump to the pressure operated means to supply nuiu pressure thereto.

5. In a transmission, a differential gear set including a plurality of relatively rotatable elements, means for connecting one of the elements to a driving shaft and a second to a driven shaft, a friction brake engageable with a third element to hold it stationary, a friction clutch to connect two elements of the gear set, and operating-means for the brake and clutch simultaneously to engage them, at least one of the operating means including a. shil'table cam and a follower engagmg the cam to move the connected brake or clutch to its engaged position when the cam is in one position, the cam being so shaped that pressure of the follower thereon acts substantially perpendicular to its surface when it is in said one position.

6. A transmission for connecting a driving shaft to a driven member comprising a hydraulic torque converter connected to the driving shaft, an intermediate shaft driven by the torque converter, a variable speed gear set connecting the intermediate shaft to the driven member, controllable elements in the gear set to change the driving condition thereof, fluid pressure 0perated means to control the controllable elements, :a pump driven by one of the shafts, a manually operable valve movable to a plurality of positions, connections through, the valve in certain of the positionstothe controllable elements, to operate said-elements selectively to select anyydesired condition of the gear set at flui-d to the second valve.

7. A transmission for connecting :a driving shaft to adriven member comprising a hydraulic torque converter connected to the driving shaft; ,an intermediate shaft driven by the torque converter, a variable speed gear set connecting the intermediate shaft to the driven member, controllableelements in the gearset to change the driving conditiont-hereof,fluid pressure opera-ted ,means ,to control the controllable e'lements, a pump driven ,by one of the shafts, a V manually operable valve movable to a plurality operated'by the engine control member in an extreme position thereof to vent the pressure on the pressure responsive means.

"8.In'a' transmission, a differential gear set including a plurality of relatively rotatable elements, means for connecting :one of the elements'towa driving shaft'and a second to a driven shaft, a friction brake engageablewithia third element tohold it stationary, a friction clutch to connect two elements of the gear-set, operating means'for' the brake and clutch including at least 3.12 one fluid {motor movable, in response to fluid pressure, control means forthe motoi to icause it to move'the operating meansto a position to efiect simultaneous engagement of the brake-and clutch, and a mechanical holding mechanism in at least one of the operating means to hold'itin its engaged position regardless of removal of the operating force by loss of pressure. in the fluid motor. V

ADIEL Y. DODGE."

REFERENCES CITED The following references are of recordin .the file of this patent:

UNITED STATES PATENTS Number Name Date 694,197 'Rose Feb. 25, 1902 716,929 Ough Dec. 30,1902 1,307,320. Von Zweibergk June 17,1919 2,055,303 Patterson Sept. 22, 1936 2,072,379 Patterson Mar. 2,1937 2,077,580 Patterson v Apr. 20,1937 2,185,538 Burtnett Jan. '2, 1940 2,194,954 Ravigneaux Mar. 26, 1940 2,195,783 Ravign-eaux Apr.,, 2, 1940 2,223,716 Bojesen Dec.'3, 1940 2,272,934 Cotal Feb. 10, 1942 2,314,554 Pennington Mar. 23, 1943 2,329,724 Maurer Sept. 21,1943 2,332,593 Nutt et a1. Oct.126,1943 2,372,817 Dodge Apr. 3, 1945 2,374,303 Osborne Apr. 24, 1945 2,407,289 La Brie Sept. 10, 1946 2,428,982 Miller ,et a1 Oct. 14,1947 2,466,244 Kelbel Apr. 5, 1949 2,516,203 Greenleeet a1 Ju1y:25, 1950 2,548,208 Evernden Apr. 10,1951 7 2,564,466 Clifton Aug. ,14, 1951 2,575,522 McFarland Nov. 20,1951

-FOREIGN PATENTS- Number Country .Date? 375,254 

